Package Exports
- image-type
This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (image-type) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.
Readme
image-type 
Detect the image type of a Buffer/Uint8Array
See the file-type module for more file types and a CLI.
Install
$ npm install image-typeUsage
Node.js
const readChunk = require('read-chunk');
const imageType = require('image-type');
const buffer = readChunk.sync('unicorn.png', 0, 12);
imageType(buffer);
//=> {ext: 'png', mime: 'image/png'}Or from a remote location:
const http = require('http');
const imageType = require('image-type');
const url = 'https://assets-cdn.github.com/images/spinners/octocat-spinner-32.gif';
http.get(url, response => {
response.on('readable', () => {
const chunk = response.read(imageType.minimumBytes);
response.destroy();
console.log(imageType(chunk));
//=> {ext: 'gif', mime: 'image/gif'}
});
});Browser
const xhr = new XMLHttpRequest();
xhr.open('GET', 'unicorn.png');
xhr.responseType = 'arraybuffer';
xhr.onload = () => {
imageType(new Uint8Array(this.response));
//=> {ext: 'png', mime: 'image/png'}
};
xhr.send();API
imageType(input)
Returns an Object with:
ext- One of the supported file typesmime- The MIME type
Or null when there is no match.
input
Type: Buffer | Uint8Array
It only needs the first .minimumBytes bytes.
imageType.minimumBytes
Type: number
The minimum amount of bytes needed to detect a file type. Currently, it's 4100 bytes, but it can change, so don't hardcode it.
Supported file types
jpgpnggifwebpflifcr2tifbmpjxrpsdicobpgjp2- JPEG 2000jpm- JPEG 2000jpx- JPEG 2000heiccurdcm- DICOM Image File
SVG isn't included as it requires the whole file to be read, but you can get it here.
License
MIT © Sindre Sorhus